1. Field of the Invention
The present invention relates to a developer supply device configured to be capable of supplying a developer to an image forming portion for forming an image with the developer comprised of powder particles by attaching the developer to a surface of an image carrier in the form of arrangement of the image, while moving the surface of the image carrier in a predetermined direction of conveyance. Also, the present invention relates to a developer for use in the same, comprised of powder particles.
2. Description of the Related Art
As this kind of developer supply device, a process cartridge is known as disclosed in, for example, JP-A No. 27845/2001. The process cartridge includes a development roller, a toner accommodating container, a toner thickness control blade, and a toner leakage restrainer.
The development roller is configured to be capable of carrying toner on its peripheral surface. The toner accommodating container accommodates therein the toner as the developer. In the toner accommodating container, is formed an opening, where the development roller is rotatably supported. The toner thickness control blade is disposed so as to be slid (sideswiped) against the peripheral surface of the development roller rotating in a predetermined direction through the opening. This toner thickness control blade is configured to be capable of forming a thin layer of the toner on the peripheral surface of the development roller. The toner leakage restrainer is configured to be capable of restraining (reducing) the leakage of the toner from a clearance between the opening, and the development roller and the toner thickness control blade to the outside of the developer supply device.
The toner leakage restrainer employs a side seal, and a lower film. The side seal is provided to be slid (sideswiped) against both ends of the development roller. The side seal is configured to be capable of restraining (reducing) the leakage of the toner from a clearance between the opening and both ends of the development roller. The lower film is provided to be slid (sideswiped) against the peripheral surface of the development roller at the lower part of the development roller (on the downstream side of the predetermined direction of rotation away from a position opposed to the image forming portion). This lower film is also configured to be capable of restraining (reducing) the leakage of the toner from the clearance between the opening and the lower part of the development roller.
In the conventional developer supply device with the above-mentioned configuration, the development roller has its peripheral surface slid (sideswiped) against the toner thickness control blade, while being rotationally driven in the direction as described above. This forms the toner thin layer on the peripheral surface of the development roller. When the development roller is rotationally driven in the above-mentioned direction, the toner thin layer is fed to the image forming portion. The peripheral surface of the development roller having passed through the image forming portion is slid (sideswiped) against the lower film, and then subjected to a toner thin layer forming operation again within the toner accommodating container.
When the number of forming image reaches a great value (for example, several thousands pieces or more of A4 size sheets) in the known developer supply device with the above-mentioned configuration, a longitudinal streak may occur in the formed image along the feed direction of an image recording medium. In identifying the inside of the developer supply device in the case of occurrence of the longitudinal streak, the toner is fusion bonded to a part of the lower film which is slid (sideswiped) against the peripheral surface of the development roller.